use "C:\Users\jkbrueck\Documents\STATA\Fuel 4\US data\Calvin3_small.dta", replace

sort type age retyr
merge m:1 type age retyr using "C:\Users\jkbrueck\Documents\STATA\Fuel 4\US data\market_values_scrap_small_append.dta"

replace type = "737 Max 8" if type == "738 Max 8"   
replace type = "737 Max 9" if type == "738 Max 9"

keep if _merge == 3
drop _merge

summarize scrap

sort airline type

save "C:\Users\jkbrueck\Documents\STATA\Fuel 4\US data\final.dta", replace


